E Daza, V Frias, A Alcola, Irene López, Iliannis Yisel Roa Bruzón, JT Montero, Luis Gonzalo Álvarez, M. Teresa Marco García, R Rodriguez, J. Boschell, Fernando de la Hoz, Favio Rivas, Víctor Alberto Olano, LA Diaz, FM Caceras, Geovanny Castro Aristizábal, Víctor M. Cárdenas, J. Cuellar, Ernesto González, A. Ruiz, Francisco Edes da Silva Pinheiro, Rosa Helena P Gusmão, Scott C. Weaver, R. B. Tesh, R. Ricco-Hesse,
An outbreak of Venezuelan equine encephalitis (VEE) that began in northwestern Venezuela in April 1995 has spread westward to the Guajira peninsula and to Colombia (Figure 1), resulting in an estimated minimum of 13,000 cases in humans and an undetermined number of equine deaths. Governments of both countries have initiated efforts to control the spread of this outbreak by quarantining and vaccinating equines and applying insecticides. This report summarizes the ongoing investigation of the outbreak ...
Tópico(s): Mosquito-borne diseases and control
1995 - Centers for Disease Control and Prevention | MMWR Morbidity and Mortality Weekly Report
José Antônio Carvalho de Ávila, Antonio Bosch, Silvio A. Aristizabal, Zenaida Frías, Víctor A. Marcial,
Ninety-seven consecutive cases of carcinoma of the pinna are reviewed in this report. Fifty-six of the tumors were basal cell and thirty-nine squamous cell carcinoma. Fifty patients were surgically treated and forty-five irradiated. Small and/or peripheral lesions were excised and the large and/or centrally located lesions referred for irradiation. Analysis of the results shows no difference in tumor control rate, and the complication rate was also comparable with both modalities. Although chondritis ...
Tópico(s): Reconstructive Facial Surgery Techniques
1977 - Wiley | Cancer
Parastoo Jamshidi, M. Aristizabal, Weihuan Kong, Victor M. Villapún, Sophie C. Cox, Liam M. Grover, Moataz M. Attallah,
One of the main challenges in additive manufacturing (AM) of medical implants for the treatment of bone tissue defects is to optimise the mechanical and biological performance. The use of post-processing can be a necessity to improve the physical properties of customised AM processed implants. In this study, Ti-6Al-4V coupons were manufactured using selective laser melting (SLM) in two build orientations (vertical and horizontal) and subsequently post-processed using combinations of hot isostatic pressing ( ...
Tópico(s): Bone Tissue Engineering Materials
2020 - Multidisciplinary Digital Publishing Institute | Materials
Víctor H. Aristizábal, Francisco J. Vélez, Édgar Rueda, Nelson Darío Gómez, Jorge A. Gómez,
Although experimental advances in the implementation and characterization of fiber speckle sensor have been reported, a suitable model to interpret the speckle-pattern variation under perturbation is desirable but very challenging to be developed due to the various factors influencing the speckle pattern. In this work, a new methodology based on the finite element method (FEM) for modeling and optimizing fiber specklegram sensors (FSSs) is proposed. The numerical method allows computational visualization ...
Tópico(s): Advanced Fiber Laser Technologies
2016 - Optica Publishing Group | Optics Express
Víctor H. Aristizábal, Francisco J. Vélez, Pedro Torres,
A numerical approach based on the scalar finite element method is applied to analyse the modal properties of photonic crystal fibers having a solid core and a cladding region with either circular or non-circular microstructured holes. A correction which accounts for the polarization effects due to the large refractive index difference between silica materials and air holes is included in the analysis. Numerical results show that the proposed technique is an efficient and accurate alternative to ...
Tópico(s): Photonic Crystals and Applications
2006 - Optica Publishing Group | Optics Express
Jorge A. Velásquez-Aristizábal, Víctor F. Camacho-Ibar, Reginaldo Durazo, José A. Valencia-Gasti, Erika Lee-Sánchez, Armando Trasviña-Castro,
In the ocean, nitrogen availability is an important control of primary production and influences the amount of energy flowing through food webs. Mesoscale eddies play important roles in modulating the spatial distributions of physical and biogeochemical properties in the Gulf of Mexico (GM), including the availability of nitrate + nitrite (NN). In this study, we explore an oceanographic station classification based on the integrated NN stock that we have named the “nitracentric classification” and a ...
Tópico(s): Marine and fisheries research
2022 - Frontiers Media | Frontiers in Marine Science
Juan Sebastián Ramírez-Navas, Jessica Aguirre-Londoño, Víctor Alexander Aristizabal-Ferreira, Sandra Patricia Castro Narváez,
El objetivo de este trabajo fue analizar el efecto de la sal sobre algunas propiedades físicas del queso, su interacción con los componentes del queso, y el efecto del contenido de sodio sobre la salud de los consumidores. La sal es un ingrediente importante, ya que determina en gran parte la calidad del producto y la aceptación del consumidor. El salado del queso tiene in uencia en la calidad debido a sus efectos sobre la composición, el crecimiento microbiano y la actividad enzimática. Ejerce ...
Tópico(s): Dye analysis and toxicity
2016 - University of Costa Rica | Agronomía Mesoamericana
Pedro Martínez‐Santos, H.F. Aristizábal, Silvia Díaz-Alcaide, Víctor Gómez‐Escalonilla,
In a context of rapid change, mapping aquatic ecosystems is crucial for their protection, particularly in regions of the world where a comprehensive inventory of water bodies is yet to be developed. This paper presents a machine learning methodology for predictive aquatic ecosystem mapping. Two state-of-the-art classifiers were used, namely support vector machines (SVM) and random forests (RFC). These were implemented in a GIS environment and trained on a sample of 350 points of a western Colombian ...
Tópico(s): Flood Risk Assessment and Management
2021 - Elsevier BV | Journal of Hydrology
Víctor H. Aristizábal, Marcela Henao-Pérez, Diana Carolina López-Medina, Renato Zambrano Cruz, Gloria Díaz-Londoño,
In this work, a preliminary study of proof-of-concept was conducted to evaluate the performance of the thermographic and blood perfusion data when emotions of positive and negative valence are applied, where the blood perfusion data are obtained from the thermographic data. The images were obtained for baseline, positive, and negative valence according to the protocol of the Geneva Affective Picture Database. Absolute and percentage differences of average values of the data between the valences ...
Tópico(s): Thermoregulation and physiological responses
2023 - Elsevier BV | Journal of Thermal Biology
Víctor H. Aristizábal, Alejandro Hoyos, Édgar Rueda, Nelson Darío Gómez, Jorge A. Gómez,
In this paper, we report some results about the effects of varying the wavelength in a structure of a non-holographic fiber specklegram sensor. In these arrangements, the speckle pattern produced by a multi-mode optical fiber is coupled to the asingle-mode optical fiber with lower numerical aperture, which produces a filtering effect that can be used as an optical transduction mechanism. The influence of the wavelength on the sensor performance is evaluated by changing the laser wavelength, and ...
Tópico(s): Optical Polarization and Ellipsometry
2015 - Springer Nature | Photonic Sensors
Megan Rose Paul, Victor Wong, Paula Aristizabal, Dennis John Kuo,
Inotuzumab ozogamicin is a novel antibody-drug conjugate that targets CD22, a common antigen on pre-B acute lymphoblastic leukemia cells.A 7-year-old boy with pre-B acute lymphoblastic leukemia in his second relapse was given 2 cycles of inotuzumab ozogamicin. He responded morphologically with a negative bone marrow evaluation. However, he relapsed in cycle 3 of therapy with a loss of CD22 expression on his lymphoblast population.To our knowledge, this is the first published case of CD22 expression ...
Tópico(s): Lymphoma Diagnosis and Treatment
2019 - Lippincott Williams & Wilkins | Journal of Pediatric Hematology/Oncology
Juan Diego Arango, Víctor H. Aristizábal, Francisco J. Vélez, Juan Carrasquilla, Jorge A. Gómez, Jairo Quijano, Jorge Herrera-Ramírez,
The published data correspond to images of simulated specklegrams, which result from the calculation of the modal interference that occurs in a multimode optical fiber. These have a characteristic pattern due to the constructive or destructive interference between the light modes depending on their phase differences. The specklegram contains valuable information since the propagation of the modes varies according to the influence of some external disturbances, and therefore, the speckle pattern ...
Tópico(s): Photonic Crystal and Fiber Optics
2023 - Elsevier BV | Data in Brief
Juan Diego Arango, Víctor H. Aristizábal, Juan Carrasquilla, Jorge Alberto Gómez, Jairo Quijano, Francisco J. Vélez, Jorge Herrera-Ramírez,
Abstract Fiber optic specklegram sensors use the modal interference pattern (or specklegram) to determine the magnitude of a disturbance. The most used interrogation methods for these sensors have focused on point measurements of intensity or correlations between specklegrams, with limitations in sensitivity and useful measurement range. To investigate alternative methods of specklegram interrogation that improve the performance of the fiber specklegram sensors, we implemented and compared two deep ...
Tópico(s): Industrial Vision Systems and Defect Detection
2021 - IOP Publishing | Journal of Physics Conference Series
Juan Diego Arango, Y.A. Vélez, Víctor H. Aristizábal, Francisco J. Vélez, Jorge A. Gómez, Jairo Quijano, Jorge Herrera-Ramírez,
The response of fiber specklegram sensors (FSSs) is given as function of variations in the intensity distribution of the modal interference pattern or speckle pattern induced by external disturbances. In the present work, the behavior of a FSS sensing scheme under thermal perturbations is studied by means of computational simulations of the speckle patterns. These simulations are generated by applying the finite element method (FEM) to the modal interference in optical fibers as a function of the ...
Tópico(s): Optical measurement and interference techniques
2021 - Samara National Research University | Computer Optics
Sandra Cano, César A. Collazos, Leandro Flórez Aristizábal, Fernando Moreira, Victor M. Peñeñory, Vanessa Agredo,
Literacy is a process where children with auditory impairments face serious difficulties in acquiring oral language, due to they must learn to listen each one of the phonetic sounds that are part of one word, so that they can learn to pronounce it and write it. Collaborative Learning (CL) applied in literacy teaching may be very favorable for children’s learning. Therefore, a model is proposed to design collaborative strategies using serious games. The model is applied to a case study that was carried ...
Tópico(s): E-Learning and Knowledge Management
2018 - Springer Nature | Advances in intelligent systems and computing
Víctor H. Aristizábal, Francisco J. Vélez, Pedro Torres,
A numerical model based on the scalar finite element method is applied to analyse the dispersion properties of photonic crystal fibers having a solid core and a cladding region with multiple air-holes. A correction which accounts for the polarization effects due to the large refractive index difference between silica materials and air holes is included in the analysis. The obtained numerical results show a good agreement with full-vector ones reported in literature.
Tópico(s): Advanced Fiber Optic Sensors
2004 - SPIE | Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Pedro Torres, Víctor H. Aristizábal, Miguel V. Andrés,
In this work, we propose a new technique for modeling light propagation in photonic crystal fibers where the electric field is evaluated from a purely transverse linearly polarized vector potential. The vector potential in a nonuniform dielectric obeys a wave equation coupled to the scalar potential, but it can be reduced to a scalar wave equation when the coupling term is ignored to the lowest order approximation. We show that this method gives reliable results for photonic crystal fibers when ...
Tópico(s): Advanced Fiber Laser Technologies
2011 - Optica Publishing Group | Journal of the Optical Society of America B
Erika Lee-Sánchez, Víctor F. Camacho-Ibar, Jorge A. Velásquez-Aristizábal, José A. Valencia-Gasti, Guillermo Samperio-Ramos,
Mesoscale eddies play an important role in modulating the vertical distributions of nutrients and primary productivity in the ocean. In this study, we evaluated the role that eddies play in determining the vertical distributions of Nitrate + Nitrite (N + N), dissolved oxygen (DO), conservative temperature (CT), and absolute salinity (SA) in the deep-water region of the Gulf of Mexico (GoM). We compared water-column profiles up to 1000 m depth and calculated the N + N stock in the euphotic layers within cyclonic ...
Tópico(s): Marine and fisheries research
2022 - Elsevier BV | Journal of Marine Systems
Adriana Patricia Villegas Quiceno, Víctor H. Aristizábal, Óscar Felipe Arbeláez Pérez, Ramón Fernando Colmenares-Quintero, Francisco J. Vélez,
At a global level, hydrokinetic power has been considered as a renewable energy source, and it has become an attractive alternative for the rural electrification of non-interconnected areas with the presence of water resources. Aspects such as the low rural electrification rate, the increase in energy demand, the decrease in fossil reserves and the climate change, are some of the factors that have driven the use of this technology for the electricity production. The aim of this work is to give a ...
Tópico(s): Wind Energy Research and Development
2021 - National University of Colombia | DYNA
Víctor H. Aristizábal, Nicolás A. Gómez-Montoya, Hernán de J. Salazar-Escobar, Francisco J. Vélez, Camilo Andrés Flórez Velásquez,
In this paper, a method for performance parameters estimation of Pockels high-voltage sensors by means of numerical optimization is presented. The proposed method integrates a theoretical model for simulation of Pockels sensors, and the optimization algorithm Pattern Search to estimate the model parameters in order to minimize the difference between the experimental and theoretical peak-peak output voltage. Two Pockels cells were built and tested for validation of the method, where model parameters ...
Tópico(s): Mechanical and Optical Resonators
2019 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Instrumentation and Measurement
Víctor H. Aristizábal, Francisco J. Vélez, Juan Jaramillo,
The diffraction of horizontally polarized shear waves by a semi-infinite wedge in frequency and time domains is studied. In particular, this work focus on the performance of different solutions, including the classical contributions from Macdonald, Sommerfeld and Kouyoumjian & Pathak. In addition, two fully analytical, simplified solutions are proposed using arguments from the so-called geometrical theory of diffraction. The main advantage of the two proposed solutions is the fact that the resulting ...
Tópico(s): Geotechnical Engineering and Soil Mechanics
2017 - Elsevier BV | Soil Dynamics and Earthquake Engineering
F. Rivas, Luis Alfonso Díaz‐Martínez, Víctor M. Cárdenas, E Daza, Leslie Bruzón, Angel C. Alcala, Orden Hoz, María Pilar Cáceres Reche, Geovanny Castro Aristizábal, José William Martínez, Desiree Rose S. Revelo, Fernando De la Hoz, J Boshell, T. Camacho, Lucie F. Calderon, Víctor Alberto Olano, L. I. Villarreal, Diego Roselli, Luis Gonzalo Álvarez, George V. Ludwig, Theodore F. Tsai,
In 1995, the first Venezuelan equine encephalitis (VEE) outbreak in Colombia in 22 years caused an estimated 75,000 human cases, 3000 with neurologic complications and 300 fatal, in La Guajira State. Of the state's estimated 50,000 equines, 8% may have died. An epizootic IC virus, probably introduced from Venezuela, was rapidly amplified among unvaccinated equines. Record high rainfall, producing high densities of vector Aedes taeniorhynchus, led to extensive epidemic transmission (30% attack rate) ...
Tópico(s): Vector-Borne Animal Diseases
1997 - Oxford University Press | The Journal of Infectious Diseases
Edwin Herrera-Cruz, Jorge Luis Aristizabal-Regino, Jonny Andrés Yepes-Blandón, Ana Estrada-Posada, José Espinosa-Araújo, Víctor Atencio-García,
El objetivo fue criopreservar semen de bagre rayado Pseudoplatystoma magdaleniatum con tres crioprotectores internos diferentes: dimetilsulfóxido (DMSO), dimetilacatamida (DMA) y etilenglicol (ETG) a dos porcentajes de inclusiones (5 y 10%), combinados con glucosa 6%, leche en polvo descremada 3% y vitamina E (0,4%). Cinco machos en fase de espermiación fueron inducidos con 0,4 ml de Ovaprim®/Kg. El semen fue diluido en la solución crioprotectora (1:3) en tubos de 2,5 ml, congelado en vapores de nitrógeno ...
Tópico(s): Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
2019 - National University of Colombia | Revista Colombiana de Biotecnología
Produção Nacional
Luis F. Castaño, Luis C. Gutiérrez, Jairo Quijano, Jorge Herrera-Ramírez, Alejandro Hoyos, Francisco J. Vélez, Víctor H. Aristizábal, L. C. da Silva-Núnez, Jorge A. Gómez,
In this work, a technique for temperature measurement using non-holographic fiber optic specklegrams is demonstrated experimentally.In the experimental scheme, a 632 nm laser source is coupled to a mono-multi-mono mode fiber arrangement, which produces a filtering effect that is used as an optical transduction mechanism.Thermal perturbations between 25 0 C and 60 0 C were applied to the fiber array, finding a linear response of the system and a sensitivity superior to the previously reported for ...
Tópico(s): Photonic and Optical Devices
2018 - | Optica Pura y Aplicada
Ivana Nieto‐Aristizábal, T. Moreno Martínez, María-Alejandra Urbano, Iván Posso‐Osorio, Ilich Plata, Juan Esteban García-Robledo, Cristian-Camilo Aragón, Víctor-Alfonso Santos, Gabriel J. Tobón,
Background Intravenous immunoglobulin (IVIG) is prepared using purified human plasma. IVIG therapy has immunomodulatory effects on autoimmune diseases, including severe systemic lupus erythematosus (SLE). However, reports of its effects on large cohorts are scarce. Methods This single-center retrospective study included SLE patients treated with at least one IVIG cycle for SLE complications. Demographic data, indications, cycle numbers, and clinical improvement with IVIG were evaluated. SLE Disease ...
Tópico(s): Chronic Lymphocytic Leukemia Research
2019 - SAGE Publishing | Lupus
En este trabajo se presenta una amplia introducción acerca de las fibras ópticas, que por tratarse de una tecnología que aún está en fase de desarrollo, es importante realizar estudios teóricos para predecir la respuesta óptica y diseñar nuevos sistemas que solucionen problemas en telecomunicaciones y sensórica. Para este fin, se emplea una herramienta de cómputo basada en el método escalar de elementos finitos para analizar cualquier tipo de guías de onda dieléctricas donde, particularmente, se ...
Tópico(s): Advanced Fiber Optic Sensors
2007 - Metropolitan Technological Institute (Medellin) | TecnoLógicas
Victor Alexander Aristizabal-Ferreira, José Manuel Guevara‐Vela, Arturo Sauza‐de la Vega, Ángel Martín Pendás, Gibrán Fuentes-Pineda, Tomás Rocha‐Rinza,
Tópico(s): Quantum Dots Synthesis And Properties
2022 - Springer Science+Business Media | Theoretical Chemistry Accounts
Jessica Aguirre-Londoño, Víctor Alexander Aristizabal-Ferreira, Sandra Patricia Castro Narváez, Juan Sebastián Ramírez-Navas,
The correlation of two instrumental techniques for chlorides determination in Colombian cheese, Queso Molido Nariñense (a type of white cheese), was analyzed. Potentiometry of chloride precipitation is the standard technique to determined salt in cheese. Conductimetry is an alternative technique. Samples of Queso Molido Nariñense were made. In the processed cheeses the salt concentration (NaCl: 0.5 %, 0.8 %, 1.0 %, 2.0 %, 3.0% and 6.0 %) was varied. Chlorides were determined by titration with silver nitrate in the ...
Tópico(s): Biochemical Analysis and Sensing Techniques
2019 - Pontifical Xavierian University | Universitas Scientiarum
Verónica Botero, Víctor Hugo Reyna García, Ana M. Aristizábal, Catalina Gómez, Paola Pérez, Luis A. Caicedo, Gabriel J. Echeverri,
Abstract Hepatitis A virus ( HAV ) causes an acute infection and is usually asymptomatic in children. When clinical manifestations appear, these include choluria, jaundice, and abdominal pain. Although infrequent, extra‐hepatic manifestations related to HAV have been described, affecting the heart, bone marrow, blood vessels, and other tissues.A 10‐year‐old boy from a rural area presented with a 15‐day history of malaise, fever, and jaundice; laboratory examinations were compatible with HAV infection. ...
Tópico(s): Viral gastroenteritis research and epidemiology
2018 - Wiley | Transplant Infectious Disease
Produção Nacional
Revisado por pares
Luis C. Gutiérrez, Luis F. Castaño, Jorge A. Gómez, Jairo Quijano, Jorge Herrera-Ramírez, Alejandro Hoyos, Luiz C. Da Silva Nunez, Francisco J. Vélez, Víctor H. Aristizábal,
Los sensores basados en el análisis de la distribución de intensidades del patrón de interferencia modal a la salida de una fibra óptica son conocidos como sensores ópticos basados en specklegramas de fibra óptica (Fiber Specklegram Sensors, FSSs). En este trabajo se muestran los specklegramas, simulados numéricamente mediante el método de los elementos finitos, de una fibra óptica Thorlabs 1550BHP perturbada mecánicamente, y se hace uso de la información global o de regiones del specklegrama mediante ...
Tópico(s): Surface Roughness and Optical Measurements
2018 - | Revista de la Academia Colombiana de Ciencias Exactas Físicas y Naturales